/*
 * Copyright (c) 2003-2010, Live Media Pty. Ltd.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice, this list of
 *     conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice, this list of
 *     conditions and the following disclaimer in the documentation and/or other materials
 *     provided with the distribution.
 *  3. Neither the name of Live Media nor the names of its contributors may be used to endorse
 *     or promote products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#include <inttypes.h>
#include <stdbool.h>
#include <endian.h>

#include "buffers.h"

#include "contiki.h"
#include "contiki-net.h"

#define BUFSIZE 256

// Receive buffer is a pointer to the UIP app data.
char * recv_buffer;
int recv_pos;

char send_buffer[ BUFSIZE ];
int send_pos;



#ifdef LITTLE_ENDIAN
 
static void swap4( unsigned char * buffer )
{
	register unsigned char b;
	
	b = buffer[0]; buffer[0] = buffer[3]; buffer[3] = b;
	b = buffer[1]; buffer[1] = buffer[2]; buffer[2] = b;
}

static void swap2( unsigned char * buffer )
{
	register unsigned char b;
	
	b = buffer[0]; buffer[0] = buffer[1]; buffer[1] = b;
}

#endif

void read_reset( char * data )
{
	recv_buffer = data;
	recv_pos = 0;
}

char * read_data( int size )
{
	char * ret = (recv_buffer+recv_pos);
	recv_pos += size;
	return ret;
}

uint8_t read_u8()
{
	return recv_buffer[recv_pos++];
}

uint16_t read_u16()
{
	uint16_t * u16 = (uint16_t *) (recv_buffer+recv_pos);
#ifdef LITTLE_ENDIAN
	swap2( (unsigned char*) u16 );
#endif
	recv_pos += 2;
	return *u16;
}

uint32_t read_u32()
{
	uint32_t * u32 = (uint32_t *) (recv_buffer+recv_pos);
#ifdef LITTLE_ENDIAN
	swap4( (unsigned char *) u32 );
#endif	
	recv_pos += 4;
	return *u32;
}


void send_clear()
{
	memset( send_buffer, BUFSIZE, 0 );
	send_pos = 0;
}

void send_write( char * data, int length )
{
	char * p = (send_buffer+send_pos);	
	send_pos += length;

	do
	{
		*p++ = *data++; length--;
	} while ( length > 0 );

}

void send_u8( char v )
{
	send_buffer[ send_pos ] = v;
	send_pos++;
}

void send_u16( uint16_t v )
{
	uint16_t * u16 = (uint16_t *) (send_buffer+send_pos);
	*u16 = v;
#ifdef LITTLE_ENDIAN
	swap2( (unsigned char *) u16 );
#endif	
	send_pos += 2;
}

void send_u32( uint32_t v )
{
	uint32_t * u32 = (uint32_t *) (send_buffer+send_pos);
	*u32 = v;
#ifdef LITTLE_ENDIAN	
	swap4( (unsigned char *) u32 );
#endif	
	send_pos += 4;
}

char * read_u8ascii( uint8_t * len)
{
	char * str;
	uint8_t x = 0;
	
	*len = recv_buffer[ recv_pos ];
	str = recv_buffer+recv_pos;
	
	while ( x < *len )
	{
		recv_buffer[recv_pos+x] = recv_buffer[recv_pos+x+1];
		x++;
	}
	
	recv_pos = recv_pos + *len;
	recv_buffer[ recv_pos++ ] = 0;
	return str;
}
